Choosing the right fish and adding them safely into your saltwater aquarium is not always a straightforward process. There are so many factors to consider when choosing the fish and once you have the right fish, you need to be conscious of the fish's health and how that fish will interact with your existing tank inhabitants. There is certainly no shortage of debate, even amongst experienced hobbyists, about the best techniques for successfully adding new fish. As a beginner, this can all seem overwhelming and the truth is, there is more than one right way to do things.

Why Is Adding New Fish So Tricky?

Not all fish are the same and different fish may have different requirements and tolerances you need to consider during acclimation.  You must consider pathogens and parasites, how will you prevent these things from getting into your aquarium?  Do you have all of the supplies and available time to quarantine new fish at home? Is it worth the extra cost of sourcing fish that have already been quarantined and medicated? These are just a few of the specific questions you will face when adding new fish but the good news is, you don't have to be a QT expert or have a biology degree to be successful. 

We distilled the process down to 7 easy steps that will help you successfully add new fish to your aquarium. 

1. Buy from a reputable retailer

Sourcing healthy fish is your first step in successfully stocking your aquarium and it all starts with finding a source you can trust. Find a local fish store that is clean and willing to discuss the health of their fish. There are also a number of great online retailers that will ship fish directly to your door and take pride in providing the healthiest possible livestock. Talk with other hobbyists, read reviews before ordering, and familiarize yourself with policies that concern the condition of the fish upon arrival to you. 

You might consider taking this a step further and finding a retailer that offers "pre-quarantined" livestock. Some retailers offer quarantine as a service in which they observe and medicate the fish before they are shipped to you. This drastically reduces the chances of disease being carried into your aquarium and also means you won't have to take the time to quarantine the fish yourself.  

2. Buy captive-bred fish

Captive-bred fish are much better suited for life in an aquarium and have much higher rates of long-term survival.  They are hardier, easier to feed, and typically have a better temperament. Since these fish are never exposed to the variety of pathogens that exist in the wild, the likelihood of them transferring disease and parasites is also much less compared to wild-caught fish. 

3. Get ready and prepare tanks

Ensure your display aquarium is cycled and gather all of the equipment you need to quarantine the fish at home. Be sure you have plenty of clean saltwater mixed up and ready to go to complete the quarantine process. A typical QT process will take 15 days from the date they are added into the QT tank.

4. Temperature acclimate

It is important for you to reduce any kind of stress caused by changing water temperatures. Simply float the bag containing your new fish in your quarantine tank for 15-25 minutes. This will equalize the water temperature inside the bag with that of your quarantine tank.

5. Drip acclimate

Drip acclimation allows the fish to slowly become adjusted to the water chemistry and conditions inside your QT tank and display. Drip acclimation is best used for fish that are shipped to you because it will slowly match the pH of the water inside the bag to the pH of the water in your quarantine tank. Fish that come from the fish store don't always have to be drip acclimated but you should always test the pH and salinity levels. If there is a dramatic difference, it's a good idea to drip acclimate for no more than 30 minutes.

6. Quarantine

Quarantining your fish is the process of isolating new fish in a separate aquarium where you can observe and medicate them so as not to transfer pathogens into your display aquarium. Even if it's a brand-new aquarium, quarantine is necessary. At a bare minimum, isolate and observe the fish for 30 days and if you notice any signs of illness or disease during this time, proceed to treat the fish with medications. You can also consider prophylactic medications which are the best way to ultimately prevent the introduction of pathogens.